Eating disorders in mums-to-be are linked to a heightened risk of asthma and wheezing in their children, irrespective of the type of disorder, presence of co-existing depression/anxiety, or the timing of their child's exposure, finds research published online in the journal Thorax.
The findings prompt the researchers to call for the inclusion of dedicated support in the healthcare of pregnant women with eating disorders to improve the respiratory health of their children.
To date, research on the effects of maternal mental health on children's respiratory health has focused predominantly on depression, anxiety, and broadly defined stress, with limited evidence on less common conditions like eating disorders, note the researchers.
And while the evidence on the consequences of maternal eating disorders has consistently reported on their children's cognitive, social, emotional, behavioural and eating behaviours, the evidence is less consistent for physical health outcomes.
To strengthen the evidence base, the researchers analysed data from 131,495 mother and child pairs from 7 distinct European birth cohorts in the EU Child Cohort Network (EUCCN) , looking at potential associations between maternal eating disorders before pregnancy and their children's preschool wheezing and school age asthma.
They subsequently explored potential associations between women who didn't have depression or anxiety by type of eating disorder (anorexia or bulimia) and period of exposure (pregnancy or after birth).
The prevalence of maternal eating disorders before pregnancy ranged from nearly 1% to 17% across the 7 cohorts. And the prevalence of co-existing depression/anxiety among women with eating disorders ranged from 11% to 75%.
The prevalence of preschool wheezing ranged from 21% to nearly 50%, while that of school age asthma ranged from just over 2% to nearly 17.5%.
An eating disorder before pregnancy was associated with an overall 25% heightened risk of preschool wheeze, although this varied considerably in each cohort, and with a 26% heightened risk of school age asthma, which was much more consistent across the cohorts.
These heightened risks weakened slightly after excluding mothers who had depression/anxiety.
Similar associations with childhood asthma were found for anorexia and bulimia, while preschool wheezing was associated with bulimia only.
Although the observed associations differed slightly across exposure periods (before, during, or after pregnancy), no distinct window of susceptibility emerged.
This is an observational study, and as such, no firm conclusions can be drawn about cause and effect, and the prevalence of eating and respiratory disorders varied widely across the cohorts.
"Although this may make some of the findings less comparable, the direction and the magnitude of the associations were relatively stable in all the analyses," explain the researchers.
But they add: "The mechanisms underlying the associations between maternal mental health and childhood respiratory outcomes remain unclear."
They suggest that mental ill health and associated stress may activate the hypothalamic-pituitary-adrenal axis, disrupting the baby's lung development during pregnancy and maturation of the child's immune system, thereby increasing susceptibility to immune mediated conditions, including asthma.
"Children born to mothers with [eating disorders] are at an increased risk of foetal growth restriction, prematurity, Caesarean delivery and low birth weight. These are also well-known risk factors for respiratory morbidity, suggesting multiple possible mediating pathways in the link between maternal [eating disorders] and childhood respiratory outcomes," they point out.
"In addition, research has shown that both mental health disorders and asthma involve dysregulation in immune response and inflammatory pathways, suggesting a common genetic basis that may contribute to both conditions," they add.
They conclude: "There is a need to include maternal [eating disorders] in research on early- life respiratory risk factors and to integrate [eating disorder] screening and support into maternal healthcare to improve respiratory outcomes in offspring."
